A method for reducing coefficients in integer linear inequalities

Approaches are considered for the reduction of coefficients in linear integer inequalities. It is shown that coefficients may be reduced easily in many practical examples. The (0-1) problem is also reconsidered and certain areas of exploration developed.     

An error components model of cost overruns and schedule slip on army R&D programs

What has been causing cost overruns and schedule slippages in Army major weapon-system R&D programs during the past ten years? This article addresses this question with emphasis on the effectiveness of an Army acquisition strategy entitled Total Risk Assessing Cost Estimating (TRACE). An empirical study employed a questionnaire and interviews with key personnel from all of the major Army Program Management Offices involved with R&D. The major research question was the following: What explanatory variables have been affecting R&D cost overruns and development time? This includes an evaluation of TRACE as a potential explanatory variable. Data was collected and analyzed using an error components multiple regression model. The major explanatory variables that appeared to explain cost overruns were technological risk of the program, education and experience of key program management office personnel, and the degree of “buy in” by the prime contractor. Strong statistical results indicate that TRACE is having little or no effect on cost overruns. In the case of development time, the major explanatory variables were seen to be technological risk of the program, testing, TRACE, education, and length of the R&D contract.     

Scheduling combat logistics force replenishments at sea for the US Navy

The Replenishment at Sea Planner (RASP) is saving the U.S. Navy millions of dollars a year by reducing fuel consumption of its Combat Logistics Force (CLF). CLF shuttle supply ships deploy from ports to rendezvous with underway U.S. combatants and those of coalition partners. The overwhelming commodity transferred is fuel, ship‐to‐ship by hoses, while other important packaged goods and spare parts are high‐lined, or helicoptered between ships. The U.S. Navy is organized in large areas of responsibility called numbered fleets, and within each of these a scheduler must promulgate a daily forecast of CLF shuttle operations. The operational planning horizon extends out several weeks, or as far into the future as we can forecast demand. We solve RASP with integer linear optimization and a purpose‐built heuristic. RASP plans Replenishment‐at‐Sea (RAS) events with 4‐hour (Navy watch) time fidelity. For five years, RASP has served two purposes: (1) it helps schedulers generate a daily schedule and animates it using Google Earth, and (2) it automates reports command‐to‐ship messages that are essential to keep this complex logistics system operating.     

Offsets as industrial policy: Lessons from aerospace

Since 1975 “offsets” have begun to appear frequently in contracts covering international sales of aircraft and other products incorporating advanced technology. Offsets involve reciprocity beyond that normally found in an exchange of goods for money. They may involve co‐production or co‐design of the principal item to be exchanged, or acceptance by the seller of goods or services unrelated to it as partial payment (indirect offsets or countertrade).

The United States has become the major provider of offsets and anti‐offset sentiment has grown. Economists interpret them as trade diverting. Politicians from regions suffering loss of employment view them as bestowing unfair advantage to foreign competitors.

The authors examine offsets from both theoretical and policy perspectives and conclude that in such noncompetitive markets, second‐best considerations dominate, requiring case‐by‐case evaluation of impacts and rendering across‐the‐board determinations of welfare loss suspect.     

Book reviews

The Political Economy of Defense, Ross A. L. (ed), Greenwood Press, 1991, New York. pp. ix, 229; ISBN 0–313–26462–7, Price $47.95

Economie Politique de la Defense, Jacques Aben, (Paris: Editions Cujas, 1992, 170 pages, 120 French Francs, ISBN: 2–254–92723‐X)     

The cost of production breaks

Disruptions in the production process can have a serious impact on production costs. Most of the previous literature which addresses the cost impact of production breaks attributes the observed increase in costs solely to “loss of learning.” We develop a mathematical model which implies that breaks in the unit learning curve can occur because of a production break, even under the assumption of no forgetting. In such cases, increases in unit cost can be caused by decreasing returns as the amount of time available to meet the delivery schedule decreases due to the production break.     

Conflict,technology, and the impact of industrialization: The Great War 1914–18

In major respects, World War I appeared markedly unlike even quite recent wars. What, by and large, caused the difference was not quality of command or changing morale. It was industrial mobilisation and technological advancement. The emergence of new weapons, and of new methods of producing them in volume and at speed, played a crucial role in changing the nature of war.

Certainly, the peculiar qualities of the Great War of 1914–18 were not determined solely by technology. Quite other factors, such as the profundity of the issues at stake ('This war is life and death'), and the relative equality in resources and determination between the principal rivals, also profoundly influenced the nature of the conflict. Yet in delineating the dominant aspects of that struggle, the contribution made by industrialization and technology and a culture of inventiveness must loom large.

Admittedly, in some respects, the transformation of weaponry under the impact of industrialisation did not necessarily produce a new kind of war. The battleship of 1914 was hugely unlike the battleship of 1805, yet the Great War at sea was not strikingly different from the naval war against Napoleon. War in the air was an entirely new phenomenon, yet the aircraft had not reached a state of development where it could fundamentally alter the face of battle.

But in the case of the land war, new weapons and new volumes of weaponry did indeed make a vast difference to the nature and consequence of military operations. In large measure they generated the features by which this struggle is best remembered: stalemate, immobility, great battles of attrition, and ‘futility’.     

PART II: CONTINUING TO QUESTION THE RELIABILITY OF NUCLEAR DETERRENCE

Responding to Derrin Culp's critique, the author argues that distinguished nuclear theorists may be wrong because groups of experts have been wrong in the past, that city attacks are central to nuclear deterrence theory because killing civilians en masse is what nuclear weapons do best, and that understanding how effective city attacks would be in war is crucial to understanding how well they would work as threats. Moreover, while it is undeniable that nuclear deterrence works some of the time, this simply is not good enough. Because any failure of nuclear deterrence could end in catastrophic nuclear war, nuclear deterrence must be perfect or almost perfect. This is a very difficult standard to reach.     

UK firms’ experience and perceptions of defence offsets: Survey results 1

Offsets are a growing feature of international trade in defence equipment. This article assesses the economics of offsets and outlines UK offsets policy. There is a lack of empirical work in the field and the article presents the results of a survey of UK firms’ experience of their involvement in offsets against UK imports of defence equipment. There is also a case study of the AWACS offset programme and an evaluation of policy implications.     

Collaborative projects and the number of partner nations

Collaborative defence projects have been a distinctive feature of European defence industrial policy. This article focuses on whether the number of partner nations in international collaborative defence and aerospace programmes is a source of inefficiency. It appears that there is not a simple linear relationship. Two nation collaborations can be efficient, but conventional wisdom assumes that inefficiencies emerge with more than two partner nations. Inevitably, data problems made what appears to be a simple hypothesis difficult to test. The major result is that there is no evidence that efficiency as measured by development times is adversely affected by the number of partner nations. A limited sample regression and a comparison of Airbus vs. Boeing shows a similar conclusion.